Mercruiser Carb Replace/Rebuild?

Good Morning ! Does anyone know what engine would be in a 1990 Cobalt 21' with a 350 Mercruiser? I guess the 350 is horsepower, but I wonder what the cubic inch or Liter size is and also is it a GM, Volvo, etc. thanks for your help Ed

I'm about to pull out my transom, I'm working on a aluminum 16' Sylvan deep V. The back of the transom is covered by aluminum, the inside is exposed but mostly under the cover that diverts the water out the drain hole. I found it very difficult when looking for marine plywood and the suggestion of to use or not to use were overwhelming. Since the only wood that is exposed is under the pan that diverts the (near the fuel containers) and all of the wood that I have pulled out of this thing so far was outdoor plywood marked "underlayment", would it be OK to use a double layer of outdoor plywood coated in resin for this? Regardless of what wood that I use, assuming that the transom has to be two layers of plywood sandwiched together, should I run the direction of the sheets opposite? Should I Gorilla Glue or Liquid nail the halves together?